In general, mainframe systems have been used to process data within large corporations and governmental organizations.
The term, mainframe system, is industrial terminology indicating a large-scale computer manufactured by a large company, e.g., IBM Corporation. Mainframe systems are mainly used for performing computations required for the business activities of large companies, such as large corporations and financial institutions, and are configured according to a centralized computing method rather than a distributed computing method.
The cost of such a mainframe system is high and rapidly increases every year. For this reason, mainframe system environments are recently being replaced by open system environments, e.g., UNIX or Linux, which are designed to enable linkage between hardware (H/W) and software (S/W) of different computer manufacturing companies, and so on.
However, totally reestablishing a conventionally used mainframe system environment as an open system environment is very costly and takes a long time.
To solve these problems, rehosting solutions have lately been developed which, when converting a mainframe system environment into an open system environment, do not reestablish the entire system but convert H/W and S/W in the conventional mainframe system environment into H/W and S/W in an open system environment using middleware, a compiler solution, etc., and reuse the H/W and S/W by a migration operation of an application program and data.
According to such rehosting solutions, however, during the migration operation of a database, many errors occur due to a difference between code systems applied to a mainframe system and an open system.